Polyamines have been associated with normal and neoplastic growth in a multiplicity of organisms. The importance of the polyamines to the stabilization of nucleoprotein structure, and their effects on biosynthesis of nucleic acids has become increasingly evident. Recent studies have shown that polyamines are probably an integral part of the eukaryotic cell nucleus, yet their function remains unclear. An extensive comparison of polyamine localization in synchronously grown populations of cultured cells at different stages of the cell cycle will be made. Special attention will be paid to facets of polyamine metabolism such as their acetylation and turnover, which might clarify their role in the nucleoprotein complex. This general approach should lead to a better understanding of the role of the polyamines and the function of the cell nucleus.